The cerebral palsy symptoms are, among others, balance and gait disorders. The goal of this study was to assess balance capabilities in children with spastic diplegic cerebral palsy rehabilitated using Lokomat active orthosis. The experimental group included children with cerebral palsy, aged 6-14 years, independent standing, level II-III according to GMFCS classification. The cohort was randomly divided into two groups. The balance was assessed on a stabilometric platform. The experimental group was administered a rehabilitation program with the use of Lokomat active orthosis. Statistically significant improvement of balance was found in the experimental group; however, in the control group the improvement was also visible, but not on the statistically significant level. While comparing the results of both groups, significantly bigger improvement was achieved by the children from the experimental group. Lokomat active orthosis is one of the newest devices applied in the rehabilitation. The study shows that training with active orthosis can have positive influence on the balance improvement in children with CP and that further analysis of the impact of such training on locomotive functions is needed.